Impact of domain wall displacements on the dielectric permittivity of epitaxial Ba0.5Sr0.5TiO3 films

Contributions of ferroelectric domain wall oscillations to the loss factor, tan delta, and the real part of the dielectric permittivity, epsilon ('), of 700 nm thick Ba0.5Sr0.5TiO3 layers were considered. The domain wall rela ted relaxation in the ferroelectric layer exhibited thermally activated beh avior with a hindering barrier phi approximate to0.08 eV. The tan delta (T) of the layer peaked and there was a hump anomaly in epsilon'(T) at a tempe rature where the relaxation rate matched the frequency of measurement. (C) 2001 American Institute of Physics.